Method and apparatus for analyzing feet

ABSTRACT

A method and apparatus for measuring feet for fitting shoes which utilizes matrixes of pressures sensors and optical sensors connected to a controller and a monitor. An apparatus of the invention includes a housing which houses a controller and a monitor and defines left and right foot wells for receiving left and right feet, respectively. The floor of each foot well includes a pressure pad assembly which includes a matrix of pressure sensor contacts covered by a variably resistive pressure pad to form pressure sensor matrixes. A digital signal processor normalizes and smooths the pressure data for display on the monitor. Infrared LED&#39;s and phototransistors are located around the perimeter of each foot well and are utilized to measure the length, width, and heights of a foot. A microprocessor addresses each LED and phototransistor separately. The controller reads data created by the DSP and IR microprocessor, calculates additional data, and displays the resulting data on the monitor. The pressure sensors and optical sensors are utilized to determine, among others, foot length, foot width, shoe size, foot volume, foot shape, force distribution, pronation, arch type, and recommended last type. Such determinations, along with intended use information obtained from the customer, are compared to a database of available shoes to determine recommended best fits for each customer. Such data can also be stored or transferred to an external system for storage with reference to each particular customer.

FIELD OF THE INVENTION

This invention relates generally to the field of analyzing feet, and inits most preferred embodiments, to integrating pressure and opticalsensors to measure feet for selecting shoes.

BACKGROUND OF THE INVENTION

It is well known that shoes and feet come in a variety of sizes andshapes. Consequently, in order to provide a particular consumer with apair of shoes, a shoe retailer must determine that particular consumer'sshoe size. If the consumer is unaware of his or her shoe size, the shoeretailer typically measures the consumer's feet to determine theappropriate shoe size. One of the most commonly used devices formeasuring feet for fitting shoes is the Branach device. This manualdevice includes two levers slidably mounted upon a labeled platform fordetermining the length and width of a particular foot. Since shoes havetraditionally been available in men, women, and children sizes, threedifferent types of Branach devices, corresponding to each of thesesizing schemes, have been utilized by shoe retailers. The manual natureof the Branach device, as well as the need for using three differentdevices for men, women, and children, suggest the need for a systemwhich automatically measures all types of feet for fitting shoes.

Various types of automatic feet measuring devices have been developed inthe past. Many of these devices utilize complex mechanical movingcomponents which are subject to ordinary shortcomings of movingmechanical parts. Other devices include one or more light sourceslocated to shine light onto the top or bottom of a foot to cast planaroutlines of the foot onto light sensitive sensors which are monitored toproduce foot length and width measurements. Although length and widthmeasurements are useful and relatively easily obtained from suchsystems, additional desirable measurements which are difficult orimpossible to obtain from such prior systems include, among others, footheight, foot volume, foot shape, and force distribution throughout thefoot.

There is a need, therefore, in the industry for a method and anapparatus for measuring feet for fitting shoes which address these andother related, and unrelated, problems.

SUMMARY OF THE INVENTION

Briefly described, the present invention, includes a method andapparatus for analyzing feet and, in its most preferred embodiment,includes a method and apparatus for measuring feet for fitting shoes. Anapparatus for accomplishing the inventive method includes a housingwhich houses a controller and a monitor and defines left and right footwells for receiving left and right feet, respectively. The floor of eachfoot well includes a pressure pad assembly which includes a matrix ofpressure sensor contacts covered by a variably resistive pressure pad toform a matrix of pressure sensors. Each pressure sensor is independentlyaddressable and includes two contacts separated by an insulated gapwhich is selectively bridged by the pressure pad to effect anindependently measurable, pressure-related resistance across theinsulated gap.

A digital signal processor (DSP) is electrically positioned between thecontroller and the pressure sensors and controls operation of thepressure sensors. During operation, a reference voltage is driven ontoone row at a time addressed through an analog multiplexer array. Theresulting current flowing from one column addressed through a secondanalog multiplexer array is converted into an amplified analog voltage.Subsequently, the analog voltage is converted into a resulting digitalrepresentation. The DSP then references a table to convert the digitalrepresentation into pounds and thereafter transfers the raw pound data,one row at a time, to the controller through a first-in-first-out (FIFO)memory resource. The DSP also conditions each row of pound data fordisplay on the monitor. A smoothing method and an auto-normalizationmethod are also employed to provide more accurate and visually appealingmonitor output screens.

Located around the inner perimeter of each foot well are opticalsensors, consisting of infrared (IR) light emitting diodes (LED's) andcorresponding phototransistors, which are utilized to measure thelength, width, and heights of a foot. A microprocessor is electricallypositioned between the controller and the optical sensors and controlsoperation of the optical sensors by addressing and driving the sensorsthrough programmable array logic circuits (PAL's) and multiplexerarrays. According to the preferred method, one LED in each foot well issupplied a modulated current while a corresponding phototransistor ischecked for receipt of the modulated signals.

Before a foot is placed in a foot well, the optical sensors operate in ascan mode which only checks every fifth LED/phototransistor pair. When afoot is placed in a foot well, thus blocking one of the optical sensors,the optical sensors enter into a tracking mode where the outer limits ofthe width, length, and height are tracked, thus saving time overrepeatedly checking every optical sensor.

When the foot wells are empty, the controller displays on the monitor aslide show of user defined screens. When the optical sensors detect afoot and enter into the tracking mode, the controller reads data createdby the DSP and IR microprocessor, calculates additional data, anddisplays the resulting data on the monitor. The pressure sensors andoptical sensors are utilized to determine, among others, foot length,foot width, shoe size, foot volume, foot shape, force distribution,pronation, arch type, and recommended last type. Such determinations,along with intended use information obtained from the customer, arecompared to a database of available shoes to determine recommended bestfits for each customer. Such data can also be stored or transferred toan external system for storage with reference to each particularcustomer.

It is therefore an object of the present invention to provide a methodand apparatus for analyzing feet for fitting shoes which includespressure sensors and optical sensors.

Another object of the present invention is to provide an apparatus forfitting shoes which includes a left pressure pad assembly and a rightpressure pad assembly, wherein each pressure pad assembly includes amatrix of independent pressure sensors which share a variably resistivepressure pad.

Another object of the present invention is to provide a method fordisplaying a visual representation of a pressure matrix which includesauto-normalization and smoothing.

Yet another object of the present invention is to provide an apparatusfor fitting shoes which includes, for each foot, length, width, andheight matrixes of optical emitters located on one side and end of afoot well and corresponding length, width, and height matrixes ofoptical receivers located on an opposing side and end of the foot well.

Still another object of the present invention is to provide a method ofusing optical sensors to efficiently track outer profile boundaries of afoot.

Still another object of the present invention is to provide a method ofintegrating foot pressure data and optical profile data to fit shoes.

Still another object of the present invention is to provide a method ofcomparing foot measurements to a database of shoes to recommend suitableshoes.

These and other objects, features and advantages of the presentinvention will become apparent upon reading and understanding thisspecification, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an Apparatus for Analyzing Feet inaccordance with the preferred embodiment of the present invention.

FIG. 2 is a left side view of the apparatus of FIG. 1.

FIG. 2(a) is a detailed view of the area "A" of FIG. 2.

FIG. 2(b) is a detailed view of the area "B" of FIG. 2.

FIG. 3 is a top view of the apparatus of FIG. 1.

FIG. 4 is a front view of the apparatus of FIG. 1.

FIG. 5 is a rear view of the apparatus of FIG. 1.

FIG. 6 is a block diagram representation of the electronic components ofthe apparatus for analyzing feet in accordance with the preferredembodiment of the present invention.

FIG. 7 is a block diagram representation of the sensor processor adapterand buttons of FIG. 6.

FIG. 8 is a block diagram representation of the mux board of FIG. 6.

FIG. 9(a) is a block diagram representation of the right pad contactboard of FIG. 6.

FIG. 9(b) is a detailed view of the are a "B" of FIG. 9(a).

FIG. 10 is a block diagram representation of the right outer IR boardand the right rear IR board of FIG. 6.

FIG. 11 is a block diagram representation of the right inner IR boardand the right front IR board of FIG. 6.

FIG. 12 is a flow chart representation of the steps taken by thecontroller of FIG. 6.

FIG. 13 is a representation of a pressure screen as displayed on themonitor.

FIG. 14 is a representation of a 3-D wire-frame screen as displayed onthe monitor.

FIG. 15 is a representation of a last screen as displayed on themonitor.

FIG. 16 is a representation of a best fit screen as displayed on themonitor.

FIG. 17 is a flow chart representation of the steps taken by theforeground processes of the pressure DSP of FIG. 7.

FIG. 18 is a flow chart representation of the steps taken by the timerinterrupt service routine of the pressure DSP of FIG. 7.

FIG. 19 is a timing diagram of signals present on the pressure sensorcontrol and data lines of FIG. 7.

FIG. 20 is a flow chart representation of the steps taken by the controlloop of the IR microprocessor of FIG. 7.

FIG. 21 is a flow chart representation of the steps taken by the sendpacket subroutine of the IR microprocessor of FIG. 7.

FIG. 22 is a flow chart representation of the steps taken by thescanning subroutine of the IR microprocessor of FIG. 7.

FIG. 23 is a flow chart representation of the steps taken by thetracking subroutine of the IR microprocessor of FIG. 7.

FIG. 24 is a flow chart representation of the steps taken by the testsubroutine of the IR microprocessor of FIG. 7.

FIG. 25 is a flow chart representation of the steps taken by the test₋₋sub subroutine of the IR microprocessor of FIG. 7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings, in which like numerals represent likecomponents throughout the several views, a foot measuring system 20, inaccordance with the preferred embodiment of the present invention, isshown in FIG. 1. A frame structure 22 is shown including a monitorhousing 25 which houses a monitor 24 and supports lighted controlbuttons 28a-e. The frame structure 22 also includes a controller housing33 and a printer housing 26 which houses a printer 30 resting on aslidably mounted printer shelf 31. Furthermore, the frame structure 22includes a left panel 35 and a right panel 37 extending outward from thecontroller housing 33 to border a sensor assembly 29.

A left foot well 70 and a right foot well 40 are shown defined by thesensor assembly 70 between the left and right panels 35, 37. The floorof the left foot well 70 is represented as a left pressure pad assembly75 including a left pad cover 91, and the floor of the right foot well40 is represented as a right pressure pad assembly 45 including a rightpad cover 61. Four infrared (IR) assemblies circumscribe each foot well40, 70. Namely, a left front IR assembly 71, a left rear IR assembly 72,a left outer IR assembly 73, and a left inner IR assembly 74circumscribe the left foot well 70; a right front right front IRassembly 41, a right rear IR assembly 42, a right outer IR assembly 43,and a right inner IR assembly 44 circumscribe the right foot well 40.

The left inner IR assembly 74 includes a left height transmitter array168 and a left length transmitter array 169 mounted upon a left inner IRboard 81 (substantially hidden from view), and the right outer IRassembly 43 includes a right height transmitter array 100 and a rightlength transmitter array 101 mounted upon a right outer IR board 50(substantially hidden from view). Although hidden from view in FIG. 1,the left outer IR assembly 73 includes a correspondingly positioned leftheight receiver array 171 and a left length receiver array 172 mountedupon a left outer IR board 80, and the right inner IR assembly 44includes a correspondingly placed right height receiver array 135 and aright length receiver array 136 mounted upon a right inner IR board 51.The left front IR assembly includes a left width receiver array 175mounted upon a left front IR board 78 (substantially hidden from view),and the right front IR assembly 41 includes a right width receiver array157 mounted upon a right front IR board 48 (substantially hidden fromview). Likewise, although hidden from view in FIG. 1, the left rear IRassembly 72 includes a correspondingly placed left width transmitterarray 180 mounted upon a left rear IR board 79, and the right rear IRassembly 42 includes a correspondingly placed right width transmitterarray 125 mounted upon a right rear IR board 49.

A center panel 36 is shown extending between the left inner IR assembly74 and the right inner IR assembly 44. The left inner IR assembly 74further includes a left inner cover 87 which substantially obscures theunderlying left inner IR board 81 and ends immediately above the leftlength transmitter array 169. The left inner cover 87 is generallyopaque except for a clear portion positioned over the left heighttransmitter array 168. A right outer cover 56 included in the rightouter IR assembly 43 is very similar to the left inner cover 87, andcorresponding covers are included in the left outer IR assembly 73 andthe right inner IR assembly 44. The left front IR assembly 71 and theright front IR assembly 41 include a left front cover 84 and a rightfront cover 54, respectively, which are completely opaque and extenddownward to locations immediately above the left width receiver array175 and the right front receiver array 157. The left rear IR assembly 72and the right rear IR assembly 42 are shown including a left kick guard39 and a right kick guard 38, respectively.

FIG. 2 shows a left side view of the foot measuring system 20. Themonitor 24 is shown extending downward into the monitor housing 25 ofthe frame structure 22, and the printer 30 is shown resting on theprinter shelf 31 mounted inside the printer housing 26. A controller 200is shown mounted inside a controller drawer 34 which is slidably mountedinside the controller housing 33. One frame wheel 23a of two 23a,b isshown mounted to the underside of the controller housing 33 of the framestructure 22.

A more detailed view of the area designated as area "A" is shown in FIG.2(a) which shows a cross-sectional view of the left panel 35, the leftrear IR assembly 72, and the left pressure pad assembly 75. The leftrear IR assembly 72 is shown including the left kick guard 39 and theleft rear IR board 79, complete with the left width transmitter array180. The left pressure pad assembly 75 is shown including a left padcontact board 90 and a left pad cover 91 which rest upon a mountingplate 21 which extends below the entire sensor assembly 29 and issupported by the kick guards 39, 38 (FIG. 1) and the left and rightpanels 35, 37 (FIG. 10). The left inner IR assembly 74 is also shownincluding the left inner cover 87 and the left inner IR board 81interposed between the left inner cover 87 and the center panel 36 andupon which the left length transmitter array 169 is mounted.

A more detailed view of the area designated as area "B" is shown in FIG.2(b) which shows a section immediately inside the left panel 35, behindthe left outer IR board 80, and adjacent the controller housing 33. Themounting plate 21 is shown supporting the left pad contact board 90 andthe left pad cover 91, and the left front IR assembly 71 is shownincluding a left gain boosting lamp 179 and the left width receiverarray 175 mounted upon the left front IR board 78 which is behind theleft front cover 84. A left sensor connector 261 is shown connecting theleft pad contact board 90 to a mux board 260 which, as is discussed ingreater detail below, is connected to a processor adapter 220 whichconnected to the controller 200 mounted inside the controller drawer 34.

FIGS. 3-5 show top, front, and rear views, respectively, of the footmeasuring system 20. Both frame wheels 23a,b are shown in FIGS. 4 and 5.Also, a floppy drive 201, power supply 202, and fan 203 are shownextending through the controller drawer 34.

FIG. 6 shows a block diagram representation of the electronic componentsof the foot measuring system 20 in accordance with the preferredembodiment of the present invention. The controller 200 is shownconnected to the monitor 24 through a monitor adapter 204 which isconnected to a controller bus 205. A controller processor 206 and randomaccess memory (RAM) are also show connected to the controller bus 205.The printer 30 is shown connected to the controller bus 205 through aninput/output (I/O) adapter 208 which also provides a link to anyexternal computers or devices. The floppy drive 201 is shown connectedto the controller bus 205 through a floppy/hard drive controller 209which is also connected to a hard drive 210. The power supply 202connects the controller 200 to an AC source, and a user may temporarilyattach a keyboard for maintenance, testing, etc. One example of anacceptable controller 200 is an industry standard personal computer (PC)with an industry standard IBM® PC AT® bus.

The controller bus 205 is also connected through a sensorprocess-controller connector 221 to the sensor processor adapter 220,which is discussed in greater detail below. The buttons 28 are shownconnected to the sensor processor adapter 220. The mux board 260, alsodiscussed in greater below, is connected to the sensor processor adapterthrough a sensor processor-mux connector 222.

A right pad contact board 60 is connected to the mux board 260 through aright sensor connector 262, to the right outer IR board 50 through aright outer connector 64, and to the right inner IR board 51 through aright inner connector 65. The right rear IR board 49 is connectedthrough a right rear connector 66 to the right outer IR board 50, andthe right front IR board 48 is connected through a right front connector67 to the right inner IR board 51. The left pad contact board 90 isconnected to the mux board 260 through the left sensor connector 261, tothe left outer IR board 80 through a left outer connector 94, and to theleft inner IR board 58 through a left inner connector 95. The left rearIR board 79 is connected through a left rear connector 96 to the leftinner IR board 81, and the left front IR board 78 is connected through aleft front connector 97 to the left outer IR board 80. Each of the rightboards 48-51, 60 are discussed in greater detail below. According to thepreferred embodiment of the present invention, the left boards 78-81, 90are essentially identical to the corresponding right boards 48-51, 60,being interchangeable therewith, and are not discussed further.

Refer now to FIG. 7, which shows a block diagram representation of thesensor processor adapter 220. The two central components of the sensorprocess adapter 220 are a digital signal processor (DSP) for thepressure system, denoted pressure DSP 230, and a microprocessor for theoptical system, denoted IR processor 244. An example of an acceptablepressure DSP 230 is the ADSP-2105KP-40 from Analog Devices of Norwood,Mass. An example of an acceptable IR processor 244 is the MC68HC11F1FNfrom Motorola of Phoenix, Ariz. In alternate embodiments, the pressureDSP 230 and IR processor 244 are combined into a single processor.

The sensor processor-controller connector 221 is shown including, atleast, a controller address bus 345 and a controller data bus 346. Thecontroller address bus 345 is shown connected to a controller addressprogrammable array logic (PAL) 214, an infrared (IR) address buffer 234,and a pressure address buffer 258. The controller data bus 346 is shownconnected to a controller data buffer 223, through which the data bus346 is connected to an IR first-in-first-out (FIFO) memory 236, an IRdata buffer 235, a control register 226, a DSP FIFO 227, and a DSP databuffer 259.

The DSP address buffer 258 is connected to a DSP address bus 229 andgates the controller address buffer 345 onto the DSP address bus 229upon receiving a control signal from the pressure DSP 230 along a busgrant line 343. One or more bits of the DSP address bus 229 are alsoconnected to a program memory 224, a data memory 225, a DSP control PAL336, and the sensor processor-mux connector 222 as read/convert selector279. The DSP control PAL 336 is connected to the data memory 225 andprogram memory 224 through data memory select line 218 and programmemory select 217, respectively, which originate with the pressure DSP230. One or more bits of the DSP data bus 228 connect between the DSPdata buffer 259, the program memory 224, the data memory 225, the DSPFIFO 227, the control register 226, the pressure DSP 230, and the sensorprocessor-mux connector 222. A DSP clock 231 is shown connected to thepressure DSP 230. The DSP decoder 335 is shown connected to the DSP FIFOthrough a FIFO written line 232, and to the control register 226 throughread handshaking bit line 337 and write handshaking bit 338. The DSPcontroller 335 also connects to a row/column enable 278 and to an A-to-Denable 280 which exit the sensor processor adapter 220 through thesensor processor-mux connector 222.

The control register 226 represents a plurality of latches and buffersdesigned to interact with the controller address PAL 226 and otherelements to control operation of the sensor processor adapter 220. Thecontroller address PAL 214 is also connected to the DSP data bufferthrough DSP data buffer enable 212, to controller data buffer 223through controller data buffer enable 213, to DSP FIFO 227 through DSPFIFO read enable 340, to the pressure DSP 230 through a DSP reset 344,and to the IR FIFO 236 through an IR FIFO read enable 341. The controlregister 226 sends signals along a DSP bus request 342 to the pressureDSP 230. The control register 226 is also connected through IRhandshaking controls 339 to IR processor 244, and through IR addressbuffer select/IR process reset 233 to IR address buffer 234, IR databuffer 235, and IR processor 244.

One or more bits of an IR address bus 239 run between the IR addressbuffer 234, an IR RAM 238, the IR processor 244, and an IR decoder 236.Also, one or more bits of an IR data bus 240 run between the IR FIFO236, the IR data buffer 235, the IR RAM 238, the IR processor 244, thebutton decoder 333, and the sensor processor-mux connector 222. A chipselect program line 254 and a chip select general purpose line 255connect the IR processor 244 to an IR control PAL 253 which, by virtueof the RAM chip select line 257, maps all writes from the IR data bus240 into the IR RAM 238 and enables the IR decoder 236 for certainaddresses on the IR address bus 239. Based on the address on IR addressbus 240, the IR decoder 236 generates signals on the right receivercontrol 247, right transmit control 248, left receiver control 249, lefttransmit control 250 (all exiting the sensor processor adapter 220through the sensor processor-mux connector 222), button decode enable332 connected to the button decoder 333, or a write FIFO line 245connected to the IR FIFO 236.

The IR processor 244 also generates signals to the button lamp control334 through button lamp control lines 331. Also, the IR process 244generates a serial peripheral interface (SPI) data signal 241, a rightSPI clock 242, and a left SPI clock 243 which exit the sensor processoradapter 220 through the sensor processor-mux connector 222. Two signals,a right IR₋₋ seen 251 and a left IR₋₋ seen 252 are shown entering the IRprocessor from the sensor processor-mux connector 222.

Refer now to FIG. 8, which shows a block diagram of the mux board 260 inaccordance with the preferred embodiment of the present invention. Thesensor processor-mux connector 222 is shown including the identicallines leaving the sensor processor adapter 220. The DSP data bus 228,row/column enable 278, read/convert selector 279, and A-to-D enable 280are shown connected to a column driver 265, and the DSP data bus 228 androw/column enable 278 are shown connected to a row driver 290. Thecolumn driver 265 includes a column latch 268 which receives input fromthe DSP data bus 228 and the row/column enable 278. An upper column muxselect 274 connects the column latch 268 to an 8:1 analog multiplexer271, and a lower column mux select 275 connects the column latch 268 toa lower column 8:1 analog mux bank 272, each of which are also connectedto the 8:1 analog multiplexer 271. A left current to voltage (I-to-V)converter bank 276 of, in the preferred embodiment, 32 converters,supplies input from left column select lines 267 which exit the muxboard 260 through the left sensor connector 261, and a right I-to-Vconvert bank 277 of, in the preferred embodiment, 32 converters,supplies input from right column select lines 266 which exit the muxboard 260 through the right sensor connector 261. Output from the 8:1analog mux 271 flows through a gain adjuster 270 and into the A-to-Dconverter 269 which supplies output onto the DSP data bus 228 accordingto control signals received through the read/convert selector and A-to-Denable 280.

The row driver 290 includes a row latch 284 receiving input from the DSPdata bus 228 and the row column selector 278. An upper row mux select288 connects the row latch 284 to an upper 1:8 mux 282, and a lower rowmux select 289 connects the row latch 284 to a lower 1:8 analog mux bank283, which also receive input from the upper 1:8 mux 282 and a voltagereference source 285 which, in the preferred embodiment, supplies -1.0volts. The output from the lower 1:8 analog mux bank 283 is connected toa voltage source bank 286 of, in the preferred embodiment, 64 sourceswhich are connected to row select lines 287 which exit the mux boardthrough both the left and right sensor connectors 261, 262.

The right receive control 247, right transmit control 248, left receivecontrol 249, and left transmit control 250 are shown connected to aright receive latch 291, a right transmit latch 292, a left receivelatch 293, and a left transmit latch 294, respectively. One of thesecontrol lines 247-250 will cause one of these latches 291-294 to latchdata from the IR data bus 240, which is also connected to each of thelatches 291-294. Output from the latches 291-294 exit the mux board 260along right receive matrix select 295, right transmit matrix select 296,left receive matrix select 297, and left transmit matrix select 298,respectively. An oscillator 314 is shown connected to a divider 311 withoutput along modulator line 312. The SPI data line 241, right SPI clockline 242, and left SPI clock line 243, along with the modulator line312, are shown connected to a left differential driver bank 263 and/or aright differential driver bank 264 to convert the TTL signals intodifferential signals right transmit SPI data lines 300, right receiveSPI data lines 303, right transmit SPI clock lines 301, right receiveSPI clock lines 304, right transmit modulator lines 299, right receivemodulator lines 302, left transmit SPI data lines 309, left receive SPIdata lines 306, left transmit SPI clock lines 310, left receive SPIclock lines 307, left transmit modulator lines 308, and left receivemodulator lines 305. The right and left IR₋₋ seen lines 251 and 252 arealso shown passing through from the sensor connectors 262, 261 to thesensor processor-mux connector 222.

FIG. 9(a) shows a block diagram representation of the right pad contactboard 60. The IR signals are shown passing through from the right sensorconnector 262 to either the right outer connector 64 or right innerconnector 65. The row select lines 287 are shown supplying current tothe rows of a right contact array 319, and the right column select lines266 are shown receiving current from the columns of the right contactarray 319. The area designated as area "B" is shown in more detail inFIG. 9(b) to include a row 1 connector 320 and a row 2 connector 326which define insulator gaps referred to as R1C1 insulator gap 322, R1C2insulator gap 323, R2C1 insulator gap 324, and R2C2 insulator gap 325.Column 1 conductor 321 and column 2 conductor 327 are shown connected tothe right column select lines 266 and protruding into the insulator gapswithout touching the row conductors 320, 326. The right pad cover 61(FIG. 1) bridges the insulator gaps to act as a matrix of pressuresensitive, variable resistors.

Refer now to FIG. 10, which shows a block diagram representation of theright outer IR board 50 and the right rear IR board 49. The right outerconnector 64 includes the right transmitter matrix select 296, righttransmit modulator lines 299, right transmit SPI clock lines 301, andright transmit SPI data lines 300. Each of the differential lines areconverted back into TTL format through a TTL driver bank 102 toreproduce modulator line 312', right SPI clock line 242', and SPI dataline 241'. Each of the reproduced lines, along with the right transmitmatrix select 296 also proceed through the right rear connector 66 tothe right rear IR board 49.

The right transmit matrix select 296 is connected along with the rightSPI clock line 242' and SPI data line 241' to a length/height (L/H)column PAL 104, an L/H row PAL 103, and a width PAL 126. The modulatorline 312' is connected to the L/H row PAL 103 and a width 1:16 row muxwhich is connected to the width PAL 126. The L/H column PAL 104 shiftsthe serial data coming from the SPI data line 241' into parallel formatand sends the upper nibble through SPI upper nibble lines 105 to alength matrix column mux 112, a heigth-1 matrix column mux 113, and aheigth-2 matrix column mux 114 and enables each through length matrixselect 107, height-1 matrix select 108, and height-2 matrix select 109based upon data received through the right transmit matrix select 296.Similarly, the width PAL shifts the upper nibble of the SPI data to awidth matrix column mux 128. The column mux's 112-114, 128 are shownconnected to pulldown arrays 115-117, 130, which effectively pullselected columns down to ground through column resistors 118 uponselection. Examples of acceptable pull down arrays are ULN-2803 fromSprague of Worcester, Mass.

The L/H row PAL 103 also shifts the SPI data, but sends the lower nibblethrough lower nibble lines 106 to a L/H row mux 110 which is connectedto a pull up array 111 which effectively supplies +12 volts to selectedrows. Similarly, the width PAL 126 sends the SPI lower nibble to a widthrow mux 127 which is connected to a pull up array 129 which supplies +12volts to selected rows. An example of an acceptable pull up array is theULN 2981A, also from Sprague. The modulator line 312' modulates the rowvoltages to, in the preferred embodiment, 40 MHz to reduce errors due tooutside light sources.

The columns from the pull down arrays 115-117, 130 and the rows from thepull up arrays 111 and 129 connect to transmitter light emitting diodes(LED's) 119 to form right length transmitter array 101, right heigth-1transmitter array 121, right height-2 transmitter array 122, and rightwidth transmitter array 125. Although electrically arranged inpartially-to-completely filled 16×16 formats for efficient control, thearrays are physically arranged as described above with respect toFIG. 1. For example, the right height-1 and height-2 transmitter arrays121, 122 combine physically to form the right height transmitter array100 shown in FIG. 1. As current flows through the transmitter LED's 119,modulated, infrared light is emitted.

Refer now to FIG. 11, which shows a block diagram representation of theright inner IR board 51 and the right front IR board 48. In a mannervery similar to the above discussion, row and column PAL's 140, 141, and159 are controlled by the right receive matrix select 295 to select alength, width, height-1, or heigth-2 matrix and activate a row andcolumn based on shifted data from the SPI data line 241'. However, pullup and pull down arrays are not utilized, and the multiplexers areanalog multiplexers 142-145, 160-161.

As light is received by a selected phototransistor 149 from one of thereceiver arrays 136-138, 157, modulated current flows through a row mux142, 161 and into a modulation filter 182, 183 to detect the modulatedsignal. Each modulation filter 182, 183 includes an I-to-V converter163, 150, two band pass filters 164, 151, a peak detector 165, 152, anda comparator 166, 153. A width IR₋₋ seen 167 and a L/H IR₋₋ seen 154 areconnected to a logical "OR" gate within the L/H row PAL 140 to producethe single right IR₋₋ seen line 251 which is connected to the rightinner connector 65.

Refer now to FIG. 12, which shows a flow chart representation of thesteps taken by the controller 200 (FIG. 6). For convenience, refer alsoto FIGS. 6 and 7. After starting at step 500, the controller 200 goesthrough initialize step 505. Subsequently, an animated slideshow runs ina loop as indicated by decision block 515 until an IR "blocked" packetappears in the IR FIFO 236. The controller programming includes a scriptmeans which facilitates modifications to the order and substance of thesteps shown in FIG. 12.

After receiving the blocked packet, the controller 200, at step 520,instructs the IR processor 244, through the control register 226, tobegin sending length/width/height packets. At step 525, the controller200 reads the DSP FIFO 227, which continually attempts to write to theDSP FIFO 227, as is discussed in greater detail below. If the pressurepacket obtained is a video packet, decision block 530 sends control tostep 535 which indicates that the video packet written directly to themonitor adapter 204, having been formatted by the pressure DSP 230, asis discussed in greater detail below. If the pressure packet is a rawdata packet, the decision block 540 and step 545 indicate that the datais written into CPU RAM 207 for analysis. Any available IR packets arethen read from the IR FIFO 236 into CPU RAM 207 at step 550 foranalysis. Calculations are then made at step 555 with all available datafrom the pressure and IR systems.

Step 560 indicates that a pressure screen is then displayed until theconsumer becomes still and the data becomes stable. Subsequent screens,activated by button 28 or timer, include a 3-dimensional screen in step565, a "last" screen for each foot at step 570, and best fit dataprompting screen at step 575. The buttons 28 are used to control screenadvancement, printing, and best fit data selections, and the function ofeach button 28 may be defined to be screen specific and displayed at thebase of each screen. After all the data is verified, the controller 200accesses a database on the hard drive 210, or through the I/O adapter toan external computer, to match available shoes to a particular consumer.All of the information obtained may also be recorded and matched to aparticular consumer for the shoe provider's future reference.

One example of an acceptable pressure screen is shown in FIG. 13. All ofthe data, including the pressure outlines are continually updated whilethe screen is displayed. Different colors indicated varying amounts ofpressure on the pressure outlines. The length and width measurements,derived from the IR packets, for each foot are shown and related to allsizing classes, i.e., man, woman, child, within which ranges the lengthand width fall. Also, three separate sizes, high medium, and low, foreach classification are shown. Adjustments are also made for consumerswho stand with feet askew. One method includes comparing the distancefrom the left-most point to the calculated center of the heel and ballof the foot from the pressure data. If the left-most point is closer tothe heel, a ratio is determined based upon the overall width to estimatethe actual width. Other methods include calculating angles based on thepressure data to more accurately determine the length and width of anangled foot.

FIG. 14 shows an example of an acceptable 3-dimensional screen whichsizes a wire-frame model to approximate the size and shape, includingarch curvature, of each of the consumer's feet. The volume, length,width, and three characteristic heights of each foot are also displayed.The controller 200 uses both pressure and IR data to compute suchmeasurements. The first height measurement is measured from the base ofthe leg, the last, at the front end of the height matrix, and themiddle, midway between the first and the last height measurements.

FIG. 15 shows an example of an acceptable "last" screen which includespreviously displayed information, along with an arch evaluation and a"last" evaluation based on pronation, and a pressure overlay of anappropriate "last." The relationships between pronation, arches, and"last" recommendations are considered understood by those reasonablyskilled in the art. FIG. 16 shows an example of a best fit dataprompting screen which prompts the consumer for information relating tothe anticipated surface type to be encountered, anticipated activities,correction of computed pronation, and special needs for surface orvolume, including whether an arch support is normally used by theconsumer.

Refer now to FIG. 17, which shows a flow chart representation of thesteps taken by the foreground process of the pressure DSP 230 (FIG. 7).For convenience, refer also to FIGS. 6-8. Before the process begins at astart step 600, the controller 200 loads the DSP program memory 224 andresets the pressure DSP 230. During an initialize step 605, the pressureDSP 230 sets variables, timer interrupts, and memory speeds, and copiesexternal variables into internal memory. After initialization, thepressure DSP 230 operates in a tight loop about step 610 which querieswhether an entire row has been scanned. After a timer interrupt is setduring the initialize step 605, the foreground process is continuallyinterrupted by the timer service routine, shown in FIG. 18.

Referring also to FIGS. 18 and 19, the timer interrupt service routine645 begins by determining whether this particular pass through theroutine is a "read" pass or a "convert" pass. If a phase variable is setto 1, the Yes branch of decision block 650 is taken to step 655 whichindicates that the A-to-D converter 269 is told to begin converting.This is accomplished by pulsing the A-to-D enable line 280 while theread/convert selector 279 is low. As is discussed below with respect tostep 725, the current row and column selects were written to the latches268 and 284 during the previous pass by driving the DSP data bus 228 andpulsing the row/column enable 278. After the A-to-D conversion isstarted, the phase variable is set to 0 at step 660, and the interruptroutine returns at step 665 to the foreground process in FIG. 17.

During the next timer interrupt, the state of the phase variable willcause control to proceed along the No branch of decision block 650 tostep 670 which again sets the phase variable to 1. Subsequently atdecision block 675, the variables row₋₋ wait and cur₋₋ row are checkedas a pacing mechanism to prevent the foreground process from overwritingthe internal data buffer. If the variables are the same, the routinereturns at step 680. If not, step 685 indicates that the timer serviceroutine causes the A-to-D converter 269 to be read and converts the datainto appropriate pressure data by referencing one or more tablesconversion tables in the program memory 224. The A-to-D read commandincludes pulsing the A-to-D enable line 280 while the read/convertselector 279 is high.

Step 690 indicates that the pressure value is then saved in the currentcolumn location (cur₋₋ col) in the data buffer and that max and minvariables are updated if the present value is higher or lower,respectively. The current column location is then updated at step 695.If the current column equals 64, the row is complete, and the Yes branchof decision block 700 is taken. Step 705 indicates that the currentcolumn location is reset to zero, and the row₋₋ complete bit is set. Thecurrent row is then incremented at step 710 and evaluated at decisionblock 715. If the current row equals 64, the current row is reset tozero, and the max and min values are written for foreground processaccess and reset for interrupt purposes. Ultimately, the current row andcolumn amounts are written to the latches 268 and 284 to scan the nextpressure cell.

Referring back to FIGS. 17 and 6-8, when the foreground process sees therow₋₋ complete bit, the Yes branch of decision block 610 is taken tostep 615 which resets the row₋₋ complete bit. At step 620, the pressureDSP 230 prepares and sends a raw data packet to the DSP FIFO 227 andsets a handshaking bit in the control register 226 to signal thecontroller 200 to read the raw data packet. At step 625, the row ofpressure data is normalized and translated into four rows of video datasuch that each sample of pressure becomes a 4×4 matrix of identicalnormalized video data.

Normalization produces a more appealing color spectrum on the monitor 24by scaling for each different consumer. The normalization processincludes mapping an actual pressure reading (P) into a video range(min₋₋ v to max₋₋ v) according to the min and max of the previous scanthrough each contact board 60, 90 (min₋₋ p and max₋₋ p). If the pressurereading is below a certain pre-set threshold value, the video valuebecomes zero. Otherwise, the normalized video value is obtained by thefollowing formula:

    min.sub.-- v+(P-min.sub.-- p)*(max.sub.-- v-min.sub.-- v)/(max.sub.-- p-min.sub.-- p).

After normalization and translation, the row₋₋ wait variable isincremented at step 630.

Step 635 indicates that the pressure DSP smooths then smooths theprevious four video rows (from the previous pressure row) using a 3×3convolution filtering method, which is considered understood by thoseskilled in the art of smoothing. At step 640, each row of video data isthen converted such that each pixel becomes a 2×2 VGA pixel matrix. Eachof the eight rows are then transmitted as video packets to the DSP FIFO227 to be read by the controller 200.

FIGS. 20-25 describe, in flow chart form, the operation of the IR systemof the preferred embodiment of the present invention. For convenience,refer also to FIGS. 6 and 7. As with operation of the pressure DSP 230,the controller 200 first loads the IR RAM 238 before the start step ofFIG. 20. After the process begins, the IR processor 244 initializes andqueries in decision block 760 whether the controller 200 is ready toreceive packets. If so, and a packet is ready to send, decision block765, (i.e., a send₋₋ type bit is set) the process jumps to the sendpacket subroutine 770, discussed in detail below.

Decision block 775 indicates that "tracking " and "scanning " actionbits are checked to determine whether the IR system is in tracking orscanning mode. The scanning mode is used when no feet are present in thefoot wells, and the tracking mode is used when feet are present,blocking one or more optical signals. Control is then transferred to theappropriate tracking or scanning subroutines 780, 785, discussed indetail below. Decision blocks 790 and 795 indicates that the status ofthe switches 28 are checked periodically. If the status has changed, the"switch " bit is set in a send₋₋ type byte which identifies ready packettypes. Subsequently, the system timers are updated in step 805.

FIG. 21 shows a flow chart representation of the send packet subroutine770. The packet type to be assembled and sent is first determined instep 810 based on the send₋₋ type byte. At step 815 the packet isassembled and transferred to the IR FIFO 236. Step 820 indicates thatthe handshaking bit in the control register 226 is toggled to notify thecontroller 200 that a packet is available. Subsequently, control isreturned in step 825.

FIG. 22 is a flow chart representation of the scanning subroutine 785.According to step 830, if an l-block or r-block bit was set during theprevious scan, the "blocked" and "data" send₋₋ type bits are set, asindicated by step 835. The "tracking" bit is set at step 840, and lengthand width variables are reset to maximum values at step 845. Control isthen returned at step 850. If an l-block or r-block bit was not setduring the previous scan, step 855 indicates that the current locationis incremented by 5 or reset if at the end. The test subroutine 860 isthen called, followed by a return at step 865.

FIG. 23 shows the tracking subroutine 780 which indicates that the nextlocation is first calculated at step 870. This step represents a"dithering" method which, with respect to one end of one line of anarray, such as the length, width, or a physical height column, movesinward from the outer most boundary until encountering a blocked signal,moving backward until the signal is cleared, and again moving inwarduntil encountering another blocked signal, thus tracking the boundary.The method rotates through the arrays and keeps track of each boundaryfor each array line for each foot. Upon encountering boundaries, thevalues are saved for placement in the data packets.

After the next locations are calculated, the tracking subroutine checksto see if both foot wells 40, 70 (FIG. 1) are empty by comparing thelast calculated boundaries. If empty, the "scanning" action bit and"empty" send₋₋ type bits are set, and the "data" send₋₋ type bit isreset. Control is then returned at step 895. If not empty, the testsubroutine 860 is initiated, followed by a return 900.

FIG. 24 represents the test subroutine 860 and immediately calls thetest₋₋ sub subroutine at step 905 which is shown in FIG. 25. Accordingto FIG. 25, the test₋₋ sub subroutine 905 selects a right transmit andright receive matrix at step 955 and sends transmitter and receiverselection data out on the SPI data line 241 to the selected rightmatrix. In the preferred embodiment, corresponding transmitter andreceiver are selected. However, alternate embodiments include selectingnon-corresponding pairs to derive additional types of data. The rightmatrixes are then disabled, and the left transmit and receive matrixesare selected and sent SPI data according to steps 965 and 970.Subsequently, the right matrixes are re-selected at step 975, andcontrol is returned to the test subroutine at step 980.

Step 910 in FIG. 10 indicates that the IR processor 244 waits for astable signal and then records the results of each IR₋₋ seen 251, 252 atthe l-block and r-block bits at step 915. The test subroutine 860 thenbegins a process of determining whether an actual boundary, rather thantrash or an error, has been encountered. At step 920, one locationcloser inward is calculated for both the left and right system andtested in test₋₋ test at step 925, followed by another wait at step 930.If blocked both times, l-block or r-block are set at step 940, or resetat step 945 if not blocked both times. Control is then returned at step950.

While the embodiments of the present invention which have been disclosedherein are the preferred forms, other embodiments of the method andapparatus of the present invention will suggest themselves to personsskilled in the art in view of this disclosure. Therefore, it will beunderstood that variations and modifications can be effected within thespirit and scope of the invention and that the scope of the presentinvention should only be limited by the claims below.

We claim:
 1. A shoe fitting apparatus comprising:a pressure means forthe generating a plurality of foot pressure signals, wherein saidpressure means includes, at least, a pressure sensitive pad means forsupporting a customer, said pressure sensitive pad means including, atleast, a matrix of pressure sensors; an optical means for generatingfoot dimension signals including, at least, foot length, foot width, andfoot height signals, wherein said optical means includes, at least,afirst plurality of optical emitters arranged in a first linear pattern,a first plurality of optical receivers arranged to receive opticalsignals from said first plurality of optical emitters, a secondplurality of optical emitters arranged in a second linear patternperpendicular to said first linear pattern, a second plurality ofoptical receivers arranged to receive optical signals from said secondplurality of optical emitters, a third plurality of optical emittersarranged in a matrix pattern located above said first and second linearpatterns, and a third plurality of optical receivers arranged to receiveoptical signals from said third plurality of optical emitters; and acontroller means for receiving said foot pressure signals and said footdimension signals and for generating and displaying show sizeinformation.
 2. An apparatus for measuring and analyzing a pair of feet,said apparatus comprising:a frame structure defining a left foot welland an adjacently located right foot well, said frame structureincluding, at least,a left well floor surface bounding a bottom of saidleft foot well, a right well floor surface bounding a bottom of saidright foot well, a left well front wall surface extendingperpendicularly up from said left well floor surface and bounding afront side of said left foot well, a right well front wall surfaceextending perpendicularly up from said right well floor surface andbounding a front side of said right foot well, a left well rear wallsurface extending perpendicularly up from said left well floor surfaceand bounding a rear side of said left foot well, a right well rear wallsurface extending perpendicularly up from said right well floor surfaceand bounding a rear side of said right foot well, a left well outer wallsurface extending perpendicularly up from said left well floor surfaceand bounding an outer side of said left foot well, a right well outerwall surface extending perpendicularly up from said right well floorsurface and bounding an outer side of said right foot well, a left wellinner wall surface extending perpendicularly up from said left wellfloor surface and bounding an inner side of said left foot well, and aright well inner wall surface extending perpendicularly up from saidright well floor surface and bounding an inner side of said right footwell; a pressure system connected to said frame structure including, atleast,a plurality of pressure sensors including, at least,a left wellmatrix of pressure sensors including, at least,a left well contact layerincluding, at least, a plurality of open sensor contacts arranged as aplanar matrix covering said left well floor surface, and a left wellpressure-sensitive, variably resistive layer covering said left wellcontact layer, a right well matrix of pressure sensors including, atleast,a right well contact layer including, at least, a plurality ofopen sensor contacts arranged as a planar matrix covering said rightwell floor surface, and a right well pressure-sensitive, variablyresistive layer covering said right well contact layer, a voltage supplymeans for continually supplying voltage to at least one pressure sensorof said plurality of pressure sensors, a current detection means forcontinually and sequentially detecting current flowing through eachpressure sensor of said plurality of pressure sensors and for generatingoutput signals representative of current flowing through each pressuresensor of said plurality of pressure sensors, and a pressure processingmeans coupled to said voltage supply means and said current detectionmeans for controlling the continual and sequential operation of saidplurality of pressure sensors and continually converting said outputsignals from said current detection means into pressure datarepresentative of pressure applied to said plurality of pressuresensors; an optical system connected to said frame structure including,at least,a left well length plurality of optical emitters extendingalong one of said left well inner wall surface and said left well outerwall surface, an opposing left well length plurality of opticalreceivers extending along the other of said left well inner wall surfaceand said left well outer wall surface, a left well height plurality ofoptical emitters extending up one of said left well inner wall surfaceand said left well outer wall surface, an opposing left well heightplurality of optical receivers extending up the other of said left wellinner wall surface and said left well outer wall surface, a left wellwidth plurality of optical emitters extending along one of said leftwell front wall surface and said left well rear wall surface, anopposing left well width plurality of optical receivers extending alongthe other of said left well front wall surface and said left well rearwall surface, a right well length plurality of optical emittersextending along one of said right well inner wall surface and said rightwell outer wall surface, an opposing right well length plurality ofoptical receivers extending along the other of said right well innerwall surface and said right well outer wall surface, a right well heightplurality of optical emitters extending up one of said right well innerwall surface and said right well outer wall surface, an opposing rightwell height plurality of optical receivers extending up the other ofsaid right well inner wall surface and said right well outer wallsurface, a right well width plurality of optical emitters extendingalong one of said right well front wall surface and said right well rearwall surface, an opposing right well width plurality of opticalreceivers extending along the other of said right well front wallsurface and said right well rear wall surface, and an optical processingmeans coupled to said pluralities of optical emitters and receivers forcontrollably causing said pluralities of optical emitters to emitoptical signals and causing said pluralities of receivers to generateelectrical signals representative of optical signals received by saidpluralities of optical emitters, and for generating, based on saidelectrical signals received from said pluralities of optical receivers,optical data representative of detected edges of any feet substantiallyrandomly located within said left well and said right well, saiddetected edges including a left well outer edge, a left well inner edge,a left well front edge, a left well rear edge, a left well upper edge, aright well outer edge, a right well inner edge, a right well front edge,a right well rear edge, and a right well upper edge; and a controllerconnected to said frame structure and coupled to said pressureprocessing means and said optical processing means, said controllerincluding, at least,a controller processor means for receiving saidpressure data from said pressure processing means and said optical datafrom said optical processing means and for calculating foot measurementdata including, at least, length, width, height, and volume data forleft and right feet based at least upon said optical data from saidoptical processing means, and a graphical display means coupled to saidcontroller processor means for displaying portions of said footmeasurement data and said pressure data.
 3. The apparatus of claim 2,wherein said controller processor means includes, at least, adjustmentmeans for accommodating angled feet by utilizing said pressure data toadjust said foot measurement data to calculate adjusted length andadjusted width data.
 4. The apparatus of claim 3, wherein saidadjustment means includes, at least, means for calculating foot angledata based upon said pressure data.
 5. The apparatus of claim 2, whereinsaid pressure processing means further includes, at least, videonormalizing means for generating normalized pressure video data forinput directly to said graphical display means.
 6. The apparatus ofclaim 2, wherein said optical processing means further includes, atleast, tracking means for continually dithering back and forth arounddetected edges.
 7. The apparatus of claim 2, wherein said controllerprocessor means utilizes said length, width, height, and volume data tocalculate a shoe size for each foot within said left and right wells. 8.An apparatus for measuring at least one foot, said apparatuscomprising:a plurality of optical sensors arranged to define a sensingarea for receipt of a foot; an optical directing means for causing saidplurality of optical sensors to employ optical signals to locate front,rear, left, and right edges of a foot substantially randomly locatedwithin said sensing area and for generating optical data representinglocated edges of the foot; and a controller means for receiving saidoptical data and for calculating and displaying foot measurement dataincluding, at least, length and width data, wherein said plurality ofoptical sensors includes, at least, a matrix of vertically arrangedoptical sensors, and wherein said optical directing means causes saidmatrix of sensors to employ optical signals to locate, at least, a firstheight of a foot at a base of a leg and a second height of a foot at asecond location nearer front of the foot.